animation: sample.ratio – R documentation

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sample.ratio

Demonstrate the ratio estimation in sampling survey

Description

This function demonstrates the advantage of ratio estimation when further information (ratio) about x and y is available.

Usage

sample.ratio(X = runif(50, 0, 5), R = 1, Y = R * X + rnorm(X), size = length(X)/2, 
    p.col = c("blue", "red"), p.cex = c(1, 3), p.pch = c(20, 21), m.col = c("black", 
        "gray"), legend.loc = "topleft", ...)

Arguments

`X`	the X variable (ancillary)
`R`	the population ratio Y/X
`Y`	the Y variable (whose mean we what to estimate)
`size`	sample size
`p.col, p.cex, p.pch`	point colors, magnification and symbols for the population and sample respectively
`m.col`	color for the horizontal line to denote the sample mean of Y
`legend.loc`	legend location: topleft, topright, bottomleft, bottomright, ... (see `legend`)
`...`	other arguments passed to `plot.default`

Details

From this demonstration we can clearly see that the ratio estimation is generally better than the simple sample average when the ratio R really exists, otherwise ratio estimation may not help.

Value

A list containing

`X`	X population
`Y`	Y population
`R`	population ratio
`r`	ratio calculated from samples
`Ybar`	population mean of Y
`ybar.simple`	simple sample mean of Y
`ybar.ratio`	sample mean of Y via ratio estimation

Author(s)

Yihui Xie

References

Examples at https://yihui.name/animation/example/sample-ratio/